Dilation introducer for orthopedic surgery

ABSTRACT

The dilation introducer has a locked assembled configuration for placement of the dilation introducer against a patient&#39;s tissue to be treated, and an unlocked, collapsed configuration for dilating the patient&#39;s soft tissue down to tissue to be treated. Dilator tubes are successively released and advanced to progressively expand the patient&#39;s soft tissue down to the bone tissue to be treated. The dilator tubes and a guide insert may include spikes for engaging bone tissue. The dilation introducer may include a light emitter disposed in a dilator tube. A telescoping expander sleeve is also provided.

CROSS-REFERENCES TO RELATED APPLICATIONS

This is a continuation-in-part of Ser. No. 10/911,215, filed Aug. 3,2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to bone fixation devices, and more particularlyrelates to a dilation introducer for introducing a bone fixation devicefor orthopedic surgery, such as for vertebral fusion.

2. General Background and State of the Art

Fusion of two adjacent vertebrae is a common surgical treatment for backinjuries due to damage or defects in a spinal disc between two adjacentvertebrae, such as conditions due to a herniated disc or discdegeneration. The entire disc may be removed by a discectomy procedure,and may be replaced with bone or a bone substitute and/or cage in orderto prevent collapse of the disc space between the adjacent vertebrae.Early techniques for stabilizing the adjacent vertebrae includedapplication of a plate or a rod in conjunction with screws across theadjacent vertebrae, after which the adjacent vertebrae would eventuallyfuse together. However, such techniques commonly required prolongedperiods of recovery from the extensive surgery involved, and it would bedesirable to provide an improved apparatus and method for providing aminimally invasive procedure that will result in less trauma andimprovement in patient recovery.

Bone fixation devices are known that are useful for connecting two ormore bone segments for the healing of broken bones, typically includingan elongate pin with a distal anchor and a proximal anchor movable onthe pin to accommodate different bone dimensions, and to permittensioning of the bone segments together. The surgical procedure ofattaching two or more parts of a bone with a pin-like device commonlyrequires an initial incision into the tissue down to the bone, and thedrilling of a hole through the bone parts to be joined. Such bonefixation devices can be useful for fusion of vertebrae together, becausesuch a bone fixation device can be used to join adjacent bone segmentsthrough a single percutaneous incision or puncture, without the need toexpose any other side of the bone segments to be joined. In either typeof procedure, there is substantial trauma to the surrounding tissue if alarge incision is required. Thus, it would be desirable to provide aminimally invasive dilation introducer to allow the penetration andspreading of soft tissues down to vertebrae to be fused, for use of sucha bone fixation device to join adjacent vertebrae, and to allow for moreeasily performing the delicate maneuvering of drilling adjacentvertebrae and application of one or more bone fixation devices to jointhe vertebrae to be fused. The present invention satisfies these andother needs.

INVENTION SUMMARY

Briefly, and in general terms, the invention provides for a telescopingdilation introducer for orthopedic surgery, the dilation introducerhaving a locked assembled configuration for initial placement of thedilation introducer against a patient's tissue to be treated, and anunlocked, collapsed configuration for dilating the patient's softsurrounding tissue to a desired degree of dilation to permit minimallyinvasive surgical procedures on the patient's tissue. As the telescopingdilation introducer is inserted, each individual dilator tube issuccessively released and advanced to progressively expand the patient'ssoft tissue down to the tissue to be treated. In a particularly usefulaspect of the invention, the tissue to be treated is bone tissue whichmust be prepared prior to attachment of adjacent bone section in afusion process. While there are many applications of the dilationintroducer of the invention, the invention is particularly applicable tofusion of bones in orthopedic surgery using minimally invasivetechnique, and will be described herein in particular applications ofthose procedures. The invention also concerns a minimally invasiveprocedure utilizing the telescoping dilation introducer to insert a bonefixation device into a patient's spine for posterior spine fusion. Whileposterior spine fusion currently takes up to two hours to complete, andrequires a six inch incision, with the apparatus and method of theinvention, comparable surgery can be completed in less than thirtyminutes, with a dilation port 13 mm or less in diameter, thus loweringthe chance of damage to the surrounding soft tissue.

A telescoping dilation introducer is typically operated by pressing theintroducer against a relatively hard surface, such as bone tissue beingtreated. The present invention provides for a guide wire assembly whensuch a telescoping dilation introducer is to used in treatment of softtissue, such as an organ, to provide a surface against which thetelescoping dilation introducer can be pushed during operation of thetelescoping dilation introducer. In a presently preferred embodiment, aguide wire or K wire assembly is provided for use with a telescopingdilation introducer according to the invention. The guide wire assemblyincludes an elongated generally cylindrical first section, and anelongated tubular second section that receives the first section. Theelongated generally cylindrical first section includes a proximalenlarged head or stop portion, and an elongated body portion with aproximal section and a relatively narrower diameter main sectionconnected to the proximal section, and a pointed distal tip at thedistal end of the narrow main section. The second section of the guidewire assembly includes an elongated tubular body with an internal boreadapted to receive the narrow main section, as is illustrated in FIG.28. The tubular second section advantageously includes a frustoconicaldistal tip with a narrowed portion at the distal end and an enlargedflat shoulder at the proximal end of the frustoconical distal tip. Whenthe guide wire assembly is assembled, the assembly presents a pointeddistal end with a proximal shoulder against which a telescoping dilationintroducer can be pushed for operation of the telescoping dilationintroducer. The main section thus adds a sharp point to the relativelyblunt distal end of the tubular distal section, allowing the guide wireassembly to be inserted through soft tissue for placement in a softtissue target of interest, such as an organ, and the first section canthen be removed to allow a telescoping dilation introducer to be placedover the second section and pressed against the shoulder of the bluntdistal end for operation of the telescoping dilation introducer. Afterthe sharp point of the guide wire is placed in the desired location inthe soft tissue, the first section can be removed from the secondsection, leaving the blunt distal end in place at the desired locationin the soft tissue, and the telescoping dilation introducer can beplaced over the second section and pressed against the shoulder of theblunt distal end for operation of the telescoping dilation introducer.

In one presently preferred embodiment, the present invention providesfor an improvement in a dilation introducer for orthopedic surgery, inwhich the dilation introducer includes one or more dilator tubes havinga distal end and a proximal end, and the distal end of the one or moredilator tubes including a plurality of spikes for engaging bone tissue.In one presently preferred aspect, the spikes may be formed ofradiopaque material, for fluoroscopic imaging of the positioning of theone or more dilator tubes, and the spikes may be formed with a roundedshape so as to deflect soft tissue.

In another presently preferred aspect, the dilation introducer includesa parallel guide insert adapted to be received in the one or moredilator tubes. The parallel guide insert includes a main cylindricalshaft having a proximal end connected to a cylindrical head, and aplurality of longitudinal bores extending the length of the parallelguide insert through the main cylindrical shaft and cylindrical head.The distal tip of the parallel guide insert may be provided with aplurality of spikes for engaging bone tissue. The spikes of the parallelguide insert may be formed of radiopaque material, and may be formedwith a rounded shape so as to deflect soft tissue.

In another presently preferred embodiment, the present inventionconcerns a dilation introducer for orthopedic surgery having a lockedassembled configuration for initial placement of the dilation introduceragainst a patient's bone tissue to be treated, and an unlocked,collapsed configuration dilating the patient's soft tissue down to thebone tissue to be treated to a desired degree of dilation to permitminimally invasive surgical procedures on the patient's bone tissue tobe treated. The dilation introducer includes a first dilator tube havinga distal end with a tapered tip and a proximal end with a cylindricalhead, and a second dilator tube having a distal end with a tapered tipand a proximal end with a cylindrical head, and an inner lumen with adistal opening and a proximal opening. The first dilator tube isremovably received in the second dilator tube for slidable telescopingmovement within the second dilator tube. Means are provided forremovably connecting the first and second dilator tubes together in alocked configuration. The means for removably connecting the first andsecond dilator tubes includes a first latching member disposed in thecylindrical head of the first dilator tube. The first latching memberhas a locking button connected transversely to a shaft with a latchingend projecting from the cylindrical head of the first dilator tubetoward the distal end of the first dilator tube, with the locking buttonextending transversely from the shaft through a side aperture in thecylindrical head of the first dilator tube. The locking button is biasedoutwardly from the cylindrical head, such as by a spring, and the firstlatching member is received in an upper aperture of the cylindrical headof an adjacent second dilator tube. The upper aperture of thecylindrical head of the second dilator tube includes a latching chamberfor retaining the latching end of the latching member when the lockingbutton is biased outwardly, to lock the cylindrical heads of the firstand second dilator tubes together. The locking button is moveableinwardly to move the latching member inwardly and to move the latchingend of the latching member inwardly out of the latching chamber, tounlock the first and second dilator tubes.

The dilation introducer may include one or more additional dilatortubes, with the second dilator tube being removably received in the oneor more additional dilator tubes for slidable telescoping movementwithin the one or more additional dilator tubes. The one or moreadditional dilator tubes likewise have a distal end and a proximal endwith a cylindrical head, an inner lumen with a distal opening and aproximal opening, and the distal end having a tapered tip. The seconddilator tube and the one or more additional dilator tubes having anunlocked configuration in which the one or more additional dilator tubesmay slidably telescope over the second dilator tube to dilate thepatient's soft tissue at the distal end of the dilation introducer.Means are provided for removably connecting the second dilator tube andthe one or more additional dilator tubes together in a lockedconfiguration. The means for removably connecting the second dilatortube and the one or more additional dilator tubes include a secondlatching member disposed in the cylindrical head of the second dilatortube. The second latching member has a locking button connectedtransversely to a shaft with a latching end projecting from thecylindrical head of the second dilator tube toward the distal end of thesecond dilator tube, and the locking button extends transversely fromthe shaft through a side aperture in the cylindrical head of the seconddilator tube. The locking button is biased outwardly from thecylindrical head, such as by a spring, and the second latching member isreceived in an upper aperture of the cylindrical head of the additionaldilator tube to be connected. The upper aperture of the cylindrical headof the additional dilator tubes include a latching chamber for retainingthe latching end of the second latching member when the locking buttonis biased outwardly, to lock the cylindrical heads of the second andadditional dilator tube together, and the locking button is moveableinwardly to move the second latching member inwardly and the latchingend of the second latching member inwardly out of the latching chamber.

In a presently preferred aspect, the additional dilator tube comprises ahandle connected to the proximal end of the additional dilator tube, andthe cylindrical head of the additional dilator tube includes a pluralityof the upper apertures, each including a latching chamber for receivingthe second latching member.

In another presently preferred embodiment, the present inventionprovides for an improvement in a dilation introducer for orthopedicsurgery, in which the dilation introducer includes a dilator tube havinga tubular shaft, a distal end and a proximal end, an inner lumen with adistal opening and a proximal opening, and a light emitter disposed inthe dilator tube. In one aspect, the light emitter may be a lightemitting diode, and the light emitting diode may be embedded in thetubular shaft of the dilator tube. In another aspect, the light emittermay include a fiber optic, and the fiber optic may be embedded in thetubular shaft of the dilator tube.

In a presently preferred aspect, the dilator tube includes a handle anda switch for controlling the light emitter, and at least one battery isdisposed in the handle and is connected to the switch to power the lightemitter. Where the light emitter includes one or more fiber optics, thelight emitter includes a light source providing light conducted to theone or more fiber optics. The light emitter may include one or moreelongated energy conducting members disposed on an outer surface of thetubular shaft of the dilator tube, and the one or more elongated energyconducting members may be disposed in a groove on the exterior surfaceof the tubular shaft. Alternatively, the one or more elongated energyconducting members may be located on the inside of the dilator tube, ormay extend through the wall of the dilator tube.

The present invention also provides for a telescoping expander sleeveadapted to be slidably disposed over a shaft of a dilator tube fordilating a patient's soft tissue down to a bone tissue to be treated toa desired degree of dilation to permit minimally invasive surgicalprocedures on the patient's bone tissue. The telescoping expander sleeveis moveable between an extended, unexpanded configuration and acollapsed, expanded configuration. The telescoping expander sleeveincludes a first generally tubular section having a tubular proximalportion and a distal portion. The tubular proximal portion has anenlarged proximal head, and the distal portion includes two or moreactive spreader arms each having a proximal end and a distal tip. Thetubular proximal portion may optionally be provided with a handle. Thetwo or more active spreader arms are connected at their proximal ends tothe tubular proximal portion, and the distal tips of the two or moreactive spreader arms are moveable radially between an unexpandedconfiguration and an expanded configuration.

The telescoping expander sleeve also includes a second generally tubularsection slidably disposed over the first generally tubular section. Thesecond generally tubular section includes a tubular proximal portion anda distal portion including two or more passive spreader flaps eachhaving a narrow proximal end and a wide distal tip. The proximal ends ofthe two or more passive spreader flaps are hingedly connected to thetubular proximal portion, and the distal tips of the two or more passivespreader flaps are moveable radially between an unexpanded configurationand an expanded configuration. The two or more active spreader armsslidably engage the two or more passive spreader flaps, so that as thetelescoping expander sleeve telescopes from the extended, unexpandedconfiguration to the collapsed, expanded configuration, the two or moreactive spreader arms slide from the narrow proximal ends of the two ormore passive spreader flaps to the wider distal ends of the passivespreader flaps to spread the distal ends of the two or more passivespreader flaps apart, and to spread the distal ends of the two or moreactive spreader arms apart.

In a presently preferred aspect, the distal tips of the two or moreactive spreader arms have beveled edges to deflect soft tissue duringinsertion of the telescoping expander sleeve, and the distal tips of thetwo or more passive spreader flaps have beveled edges to deflect softtissue during insertion of the telescoping expander sleeve. The purposeof the active spreader arms and passive spreader flaps is to facilitatethe creating of a larger working area adjacent to bone or bone tissuesbeing treated. The spreader arms and flaps may optionally be covered byan expandable material, such as latex, for example, to prevent tissuesfrom being pressed into cavities of the telescoping expander sleeve.

While the present invention is particularly useful for the purposes oforthopedic surgery, those skilled in the art will recognize that theinvention can also be used for the treatment of a variety of internalorgans or structures when it is desired to minimize the size of anopening in the patient's soft tissue and the resultant damage and traumato tissue surrounding the operation site.

Other features and advantages of the present invention will become moreapparent from the following detailed description of the preferredembodiments in conjunction with the accompanying drawings, whichillustrate, by way of example, the operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a first embodiment of a dilation introducer ina locked configuration, according to the present invention.

FIG. 2 is a plan view of the dilation introducer of FIG. 1 shown in anunlocked, collapsed configuration.

FIG. 3 is a plan view of the first or inner dilator tube of the dilationintroducer of FIG. 1.

FIG. 4 is a plan view of the second or intermediate dilator tube of thedilation introducer of FIG. 1.

FIG. 5 is a plan view of the third or outer dilator tube of the dilationintroducer of FIG. 1.

FIG. 6A is a top plan view of the first locking clip of the dilationintroducer of FIG. 1.

FIG. 6B is an elevational view of the first locking clip of the dilationintroducer of FIG. 1.

FIG. 6C is a bottom plan view of the first locking clip of the dilationintroducer of FIG. 1.

FIG. 7A is a top plan view of the second locking clip of the dilationintroducer of FIG. 1.

FIG. 7B is an elevational view of the second locking clip of thedilation introducer of FIG. 1.

FIG. 8 is a perspective view of a second embodiment of a dilationintroducer in a locked configuration, according to the presentinvention.

FIG. 9 is a perspective view of the dilation introducer of FIG. 8 shownin an unlocked, collapsed configuration.

FIG. 10 is a perspective view of the first or inner dilator tube of thedilation introducer of FIG. 8.

FIG. 11 is a perspective view of the second or intermediate dilator tubeof the dilation introducer of FIG. 8.

FIG. 12 is a plan view of the third or outer dilator tube of thedilation introducer of FIG. 8.

FIG. 13 is a plan view of a third embodiment of a dilation introducer ina locked configuration, according to the present invention.

FIG. 14 is a plan view of the dilation introducer of FIG. 13 shown in anunlocked, collapsed configuration.

FIG. 15 is a plan view of the first or inner dilator tube of thedilation introducer of FIG. 13.

FIG. 16 is a plan view of the second or intermediate dilator tube of thedilation introducer of FIG. 13.

FIG. 17 is a plan view of the third or outer dilator tube of thedilation introducer of FIG. 13.

FIG. 18 is a plan view of the plastic sleeve of the dilation introducerof FIG. 13.

FIG. 19 is a plan view of a fourth embodiment of a dilation introducerin a locked configuration, according to the present invention.

FIG. 20 is a plan view of the dilation introducer of FIG. 19 shown in anunlocked, collapsed configuration.

FIG. 21 is a plan view of the first or inner dilator tube of thedilation introducer of FIG. 19.

FIG. 22 is a plan view of the second or intermediate dilator tube of thedilation introducer of FIG. 19.

FIG. 23 is a plan view of the third or outer dilator tube of thedilation introducer of FIG. 19.

FIG. 24 is a schematic diagram illustrating location of a starting pointfor insertion of a bone fixation device according to the method of theinvention.

FIG. 25 is a schematic diagram of a lateral view illustrating locationof a trajectory for insertion of a bone fixation device according to themethod of the invention.

FIG. 26 is a schematic diagram of an anterior view illustrating locationof a trajectory for insertion of a bone fixation device according to themethod of the invention.

FIG. 27 is a plan view of a guide wire assembly for use with the variousembodiments of the telescoping dilation introducer of the invention,shown disassembled.

FIG. 28 is a plan view of the guide wire assembly of FIG. 27, shownpartially assembled.

FIG. 29 is a plan view of the guide wire assembly of FIG. 27, shownfully assembled.

FIG. 30 is a perspective view of a variation of the outer dilator tubeof the embodiment of FIGS. 8-12, with a parallel guide.

FIG. 31 is a perspective view of the parallel guide from FIG. 30.

FIG. 32 is a perspective view of a variation of the outer dilator tubeof the embodiment of FIGS. 8-12, with an angled tip and with a parallelguide.

FIG. 33 is a perspective view of the parallel guide with an angled tipfrom FIG. 32.

FIG. 34 is a perspective of another variation of the outer dilator tubeof the embodiment of FIGS. 8-12, with an angled tip and spikes.

FIG. 35 is a perspective view of the outer dilator tube of FIG. 34, witha parallel guide with spikes.

FIG. 36 is a perspective view of a fifth embodiment of a dilationintroducer in an unlocked configuration, according to the presentinvention.

FIG. 37 is a sectional view of a portion of the dilation introducer ofFIG. 36.

FIG. 38 is a perspective view of a variation of the dilation introducerof FIG. 36, shown in a locked configuration, according to the presentinvention.

FIG. 39 is a sectional view of a portion of the dilation introducer ofFIG. 36 taken along line 39-39 of FIG. 38.

FIG. 40 is a top perspective view of the head end of the handle of thedilation introducer of FIG. 36, showing multiple locking locations.

FIG. 41 is a schematic diagram of a variation of the dilation introducerof FIG. 36, with a light emitter and switch for the light emitter.

FIG. 42 is an enlarged view of the tip of the dilation introducer ofFIG. 41.

FIG. 43 is a perspective view of another variation of the dilationintroducer of FIG. 41, with an exterior groove for one or more elongatedenergy conducting members.

FIG. 44 is a side elevational view of a telescoping expander sleeveshown in an extended, unexpanded configuration.

FIG. 45 is a side elevational view of the telescoping expander sleeve ofFIG. 44 shown in an intermediate partially collapsed, partially expandedconfiguration.

FIG. 46 is a side elevational view of the telescoping expander sleeve ofFIG. 44 shown in a fully collapsed, fully expanded configuration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, which are provided for purposes ofillustration and by way of example, the present invention provides for atelescoping dilation introducer for orthopedic surgery, the dilationintroducer having a locked assembled configuration for initial placementof the dilation introducer against a patient's bone tissue to betreated, and an unlocked, collapsed configuration dilating the patient'ssoft tissue down to the bone tissue to be treated to a desired degree ofdilation to permit minimally invasive surgical procedures on thepatient's bone tissue to be treated.

While the invention will be described with specificity to a spinalfusion procedure, those skilled in the art will recognize that theapparatus and method of the art will recognize that the apparatus andmethod of the invention can also be advantageously used for proceduresin which the dilation introducer can be brought up against other firm orsolid structures in the body or introduced into the body to thereby gainthe advantages of the invention for other minimally invasive procedures.

A dilation introducer 30 according to a first preferred embodiment isshown in a locked assembled configuration in FIG. 1, and shown in anunlocked, collapsed configuration in FIG. 2. Referring to FIG. 3, thedilation introducer includes a first or inner dilator tube 32 having adistal end 34 with a tapered tip 36, and a proximal end 38 with a head40 including a pair of spaced part rings 42. The first dilator tube hasan inner lumen 44 with a distal opening 46 and a proximal opening 48.

Referring to FIG. 4, the dilation introducer also includes a shortersecond or intermediate dilator tube 52 having a distal end 54 with atapered tip 56, and a proximal end 58 with a head 60 including a pair ofspaced apart rings 62. The second dilator tube has an inner lumen 64with a distal opening 66 and a proximal opening 68.

Referring to FIG. 5, in a presently preferred aspect, the dilationintroducer also includes at least one additional dilator tube, such as astill shorter third or outer dilator tube 72 having a distal end 74 witha tapered tip 76, and a proximal end 78 with a handle 80. The thirddilator tube has an inner lumen 82 with a distal opening 84 and aproximal opening 86.

Referring to FIGS. 6A, 6B and 6C, the means for removably connecting thefirst and second dilator tubes together in a locked configurationincludes a first locking clip 88. As is shown in FIGS. 7A and 7B, ameans for removably connecting the second and third dilator tubestogether in a locked configuration may also be provided, and may includea second locking clip 90. The first locking clip includes a firstportion 92 and a second portion 94, and a cross-piece or handle 96having a first end 98 and a second end 100 connected at right anglesbetween the first and second portions. The first portion includes pairof resilient arms 102 each having a proximal narrow neck portion 104connected to the cross-piece, and a distal gripping portion 106extending from the narrow neck portion. The resilient arms have an innerrounded surface 108 adapted to snap over the first dilator tube betweenthe spaced apart rings of the first dilator tube. The second portioncurrently preferably includes a single arm 112 having a proximal narrowneck portion 114, and a distal gripping portion 116 extending from thenarrow neck portion. The gripping portion has an inner rounded surface118 adapted to fit over the outer surface of the second dilator tubebetween the spaced apart rings of the second dilator tube, to connectthe first and second dilator tubes. Removing the first locking clipallows the second or intermediate dilator tube to slidably telescopeover the first inner dilator tube to dilate tissue at the distal end ofthe dilation introducer.

The second locking clip includes a first portion 122 and a secondportion 124, and a cross-piece or handle 126 having a first end 128 anda second end 130 connected between the first portion and the secondportion at right angles. The first portion includes a pair of resilientarms 132 each having a proximal narrow neck portion 134 connected to thecross-piece, and a distal gripping portion 136 extending from the narrowneck portion. The pair of resilient arms have an inner rounded surface138 adapted to snap over the outer surface of the second dilator tubebetween the spaced apart rings of the second dilator tube. The secondportion of the second locking clip includes a pair of resilient arms 142each having a proximal narrow neck portion (not shown) connected to thecross-piece and a distal gripping portion 146 extending from the narrowneck portion, the pair of resilient arms having an inner rounded surface(not shown) adapted to fit over the outer surface of the third dilatortube to connect the second and third dilator tubes. Removing the secondlocking clip allows the third or outer dilator tube to slidablytelescope over the second inner dilator tube to further dilate tissue atthe distal end of the dilation introducer.

As is shown in FIG. 1, a tubular bone drill or tap 150 can be insertedthrough an intermediate or outer dilator tube, and the tubular bonedrill or tap can be passed or threaded over a guide wire or K wire 151to contact the surface of the vertebra or bone to be treated, as will befurther described below. Once the outer dilator tube has been moved tothe distal end of the dilation introducer into position against thevertebra or bone to be treated to fully dilate the soft tissue, theinner dilator tube, the tubular bone drill, and the intermediate dilatortube can be withdrawn and removed to leave the outer dilator tube inplace to permit further surgical procedures.

Referring to FIGS. 8-12, the invention provides for a second presentlypreferred embodiment of a dilation introducer 160 shown in a lockedassembled configuration in FIG. 8, and shown in an unlocked, collapsedconfiguration in FIG. 9. Referring to FIG. 10, the dilation introducerincludes a first or inner dilator tube 162 having a distal end 164 witha tapered tip 166, and a proximal end 168 with a cylindrical head 170.The means for removably connecting the first and second dilator tubestogether in a locked configuration includes a latching member 172, suchas a hook, projecting from the cylindrical head toward the distal end,receiving a locking pin 216, although other latching members, such as aprojection with aperture for receiving a locking pin may also besuitable, as will be apparent from the explanation below. The firstdilator tube has an inner lumen 174 with a distal opening 176 and aproximal opening 178.

Referring to FIG. 11, the dilation introducer includes a shorter secondor intermediate dilator tube 182 having a distal end 184 with a taperedtip 186, and a proximal end 188 having a cylindrical head 190. The meansfor removably connecting the second and third dilator tubes together ina locked configuration includes a latching member 192, such as a hook,projecting from the cylindrical head toward the distal end, receiving alocking pin 218, although other latching members, such as a projectionwith aperture for receiving a locking pin may also be suitable, as notedabove. The second dilator tube has an inner lumen 194 with a distalopening 196, and a proximal opening 198. The cylindrical head includes afirst radial aperture 200 for receiving the locking pin 216, and asecond longitudinal aperture 201 for receiving the distally projectinglatching member of the cylindrical head of the first or inner dilatortube.

Referring to FIG. 12, in a preferred aspect, the dilation introducerincludes at least one additional dilator tube, such as a still shorterthird or outer dilator tube 202 having a distal end 204 with a taperedtip 206, and a proximal end 208 to which a handle 210 is connected atits head end 212. The head end of the handle includes a radial aperture214 for receiving the locking pin 218, and a longitudinal aperture 215for receiving the distally projecting latching member of the cylindricalhead of the second or intermediate dilator tube. The first locking pin216 is substantially the same as the second locking pin 218. The thirddilator tube has an inner lumen 219 with proximal and distal openings. Atubular bone drill or tap can be inserted through the first or innerdilator tube, and the tubular bone drill or tap can be threaded over aguide wire or K wire to contact the surface of the vertebra or bone tobe treated, as described above.

With reference to FIGS. 13-18, the invention provides for a thirdpresently preferred embodiment of a dilation introducer 220, shown in alocked assembled configuration in FIG. 13, and shown in an unlocked,collapsed configuration in FIG. 14. As is illustrated in FIG. 15, thedilation introducer includes a first or inner dilator tube 222 having adistal end 224 with a tapered, beveled tip 226, and a proximal end 228with a cylindrical head 230. The means for removably connecting thefirst and second dilator tubes together in a locked configurationincludes a pair of opposing bayonet pins 232 extending from the proximalend of the first dilator tube. The first dilator tube has an inner lumen234 with a distal opening 236 and a proximal opening 238.

As is shown in FIG. 16, the dilation introducer includes a shortersecond or intermediate dilator tube 242 having a distal end 244 with atapered, beveled tip 246, and a proximal end 248 with a cylindrical head250. In a preferred aspect, a means for removably connecting the secondand third dilator tubes together in a locked configuration includes apair of opposing bayonet pins 252. The second dilator tube has an innerlumen 254 with a distal opening 256 and a proximal opening 258, and aspart of the means for removably connecting the second and third dilatortubes together, interior opposing bayonet slots 260 for receiving thepair of opposing bayonet pins of the first or inner dilator tube.

Referring to FIG. 17, in a preferred aspect, the dilation introducerincludes at least one additional dilator tube, such as a still shorterthird or outer dilator tube 262 having a distal end 264 with a taperedtip 266, and a proximal end 268 having a pair of opposing handles 270.The third dilator tube has an inner lumen 271, with proximal and distalopenings. In another presently preferred aspect, a plastic sleeve 272 isslidably disposed over the shaft of the third or outer dilator tube, andthe plastic sleeve preferably has a distal tapered, beveled end 274. Aproximal sleeve ring 276 may also be slidably disposed over the shaft ofthe third or outer dilator tube between the plastic sleeve 272 and theopposing handles.

As is illustrated in FIGS. 13 and 14, in this embodiment the taperedtips of the dilator tubes and plastic sleeve are beveled or angled at acommon angle with respect to the longitudinal axis of the dilationintroducer, so that the beveled edges of the tapered tips of the dilatortubes and plastic sleeve can be aligned together generally parallel tothe surface of the soft tissue to be dilated, so that the bore anddilation passage of the dilation introducer may be aligned at apredetermined desired angle with respect to the soft tissue to bedilated and the bone tissue to be treated.

As part of the means for removably connecting the second and thirddilator tubes together, the third dilator tube includes interioropposing bayonet slots 278 for receiving the pair of opposing bayonetpins of the second or intermediate dilator tube. A tubular bone drill ortap can be inserted through the first or inner dilator tube, and thetubular bone drill or tap can be threaded over a guide wire or K wire tocontact the surface of the vertebra or bone to be treated, as describedabove.

With reference to FIGS. 19-23, the invention provides for a fourthembodiment of a dilation introducer 280 shown in a locked assembledconfiguration in FIG. 19, and shown in an unlocked, collapsedconfiguration in FIG. 20. Referring to FIG. 21, the dilation introducerincludes a first or inner dilator tube 282 having a distal end 284 witha tapered tip 286, and a proximal end 288 having a generally sphericalhandle or head 290. As part of a means for removably connecting firstand second dilator tubes together in a locked configuration, theproximal end of the first dilator tube near the handle includes abayonet pin 292. The first dilator tube has an inner lumen 294 with adistal opening 296, and a proximal opening 298.

Referring to FIG. 22, the dilation introducer includes a shorter secondor intermediate dilator tube 302 having a distal end 304 with a taperedtip 306, and a proximal end 308 having a generally cylindrical head 310and a pair of opposing handles 312. The second dilator tube has an innerlumen 314 with a distal opening 316 and a proximal opening 318. As partof the means for removably connecting first and second dilator tubestogether in a locked configuration, the proximal end of the seconddilator tube includes a bayonet slot 320 formed in the cylindrical headfor receiving the bayonet pin of the first or inner dilator tube.

Referring to FIG. 23, in a preferred aspect, the dilation introducerincludes at least one additional dilator tube, such as a still shorterthird or outer dilator tube 322, currently preferably formed of plastic,having a distal end 324 with a tapered tip 326, and a proximal end 328with a generally cylindrical head end or handle 330. The third dilatortube has an inner lumen 332, with proximal and distal openings. Atubular bone drill or tap can be inserted through the first or innerdilator tube, and the tubular bone drill or tap can be threaded over aguide wire or K wire to contact the surface of the vertebra or bone tobe treated, as described above.

Facet Screw Surgical Technique:

Referring to FIGS. 24-26, a surgical method for spinal fusion utilizingthe dilation introducer apparatus and a bone fixation device such as abone fixation device available under the trade name BONE-LOK from TriageMedical, Inc. of Irvine, Calif., is described. Alternatively, othertypes of bone screws or fixation devices may also be suitable. Themethod of the invention involves dilating a patient's soft tissue downto bone tissue to be treated in orthopedic surgery, and necessarilyentails an incision and fluoroscopy to locate an entry point on the bonetissue to be treated.

An entry point is located on the bone tissue to be treated, and the tipof a guide wire or K-wire 151 is placed at the entry point on the bonetissue to be treated shown in FIG. 25, and driven into the soft tissueof the patient to the target point of the inferior articular facet. Avertical midline incision to a desired depth, such as approximately 17mm, is made in the skin and fascia of the patient, using the entry pointas the middle of the incision. A first dilator tube of the dilationintroducer is then passed over the guide wire until the tip of thedilation introducer reaches the target point of the bone. The guide wireis then driven into the facet joint and into the pedicle of the patient,with verification of the trajectory and depth by fluoroscopy. The seconddilator tube of the dilation introducer is then released and passed overthe first dilator tube to allow it to progress to the bone, allowingremoval of the first dilator tube. This is repeated for the remaining,progressively wider telescoping dilator tubes, to progressively expandthe patient's soft tissue down to the entry point on the bone tissue tobe treated, and leaving an outer dilator tube port in place. A depthgauge is then used to verify that the appropriate depth has beenreached. A pre-drill is advanced to the desired location, which is thenalso verified by fluoroscopy. A cortex drill is advanced until itspositive stop engages, and the distal tip of a tap is driven into thebone until it reaches the appropriate depth, which is then also verifiedby fluoroscopy. The drill can be connected through an AO style quickconnect, or a Jacobs chuck, as long as they are fully cannulated, to aratcheting handle which is also preferably cannulated. A bone fixationdevice is then driven into the bone until it reaches the appropriatedepth, which is then also verified by fluoroscopy. The bone fixationdevice is compressed to achieve appropriate stabilization, which is thenalso verified by fluoroscopy. Once compression of the bone fixationdevice has been achieved, the pull pin is removed, the guide wire isremoved, and the remaining outer dilator tube port is removed, and theincision can be closed normally.

Referring to FIGS. 27-29, in one presently preferred embodiment, a guidewire or K wire assembly 340 for use with the telescoping dilationintroducer of the invention includes an elongated, generally cylindricalfirst section 342 and an elongated, tubular second section 344 that isadapted to receive the first section. The first section includes aproximal enlarged head or stop portion 346, and a relatively narrowelongated body portion 348. The elongated body portion is preferablyformed with a proximal section 350 having a relatively larger diameterto provide relatively greater strength, rigidity and torquability formanipulation of the guide wire, and a relatively narrower diameter mainsection 352 connected to the proximal section, and a pointed distal tip354 at the distal end 358 of the main section. The elongated tubularsecond section has a relatively larger diameter than the main sectionand an internal bore slightly larger in diameter than the main sectionfor receiving the main section, as is illustrated in FIG. 28. Thetubular second section advantageously also includes a frustoconicaldistal tip 362 with a narrowed portion 364 at the distal end 366 of thetubular distal section, and presenting an enlarged flat shoulder 368 atthe proximal end of the frustoconical distal tip, so that when the guidewire assembly is assembled as shown in FIG. 29, and the elongated mainsection is received in the internal bore of the elongated tubularsection, and the proximal section of the elongated body portion of theelongated generally cylindrical section is seated against said proximalend of said elongated tubular section, the pointed distal tip extendsout of said frustoconical distal tip of said elongated tubular sectionso that the assembly presents a pointed distal end, with a proximalshoulder against which a telescoping dilation introducer can be pushedfor operation of the telescoping dilation introducer. The elongatedgenerally cylindrical first section thus adds a sharp point to therelatively blunt distal end of the elongated tubular second section,allowing the guide wire assembly to be inserted through soft tissue forplacement in a soft tissue target of interest, such as an organ. Sincethe soft tissue present no hard surface against which the telescopingdilation introducer can be pushed, after the sharp point of the guidewire is placed in the desired location in the soft tissue, the firstsection can be removed from the second section, leaving the blunt distalend in place at the desired location in the soft tissue, and thetelescoping dilation introducer can be placed over the second sectionand pressed against the shoulder of the blunt distal end for operationof the telescoping dilation introducer.

As is shown in FIG. 30, in one presently preferred variation of the atleast one additional or outer dilator tube, such as in the embodiment ofFIGS. 8-12 for example, the outer dilator tube 400 includes a parallelguide insert 402, shown in FIG. 31. The outer dilator tube has a distalend 404 with a tapered tip 406, and a proximal portion 408 to which ahandle 410 is connected at the extreme proximal or head end 412 of theouter dilator tube. The head end of the outer dilator tube includes aradial aperture 414 for receiving the locking pin 416, and alongitudinal aperture 418 for receiving a distally projecting latchingmember 420 of the cylindrical head 422 of the parallel guide insert. Theouter dilator tube has an inner bore 424 with proximal and distalopenings.

The parallel guide insert includes a main cylindrical shaft 425connected at a proximal end 426 to the cylindrical head of the parallelguide insert. The parallel guide insert includes a plurality oflongitudinal bores 428 extending the length of the parallel guide insertfrom the distal end 430, with distal openings visible in FIG. 31, toproximal openings (not shown) in the cylindrical head of the parallelguide insert. The insertion of the distally projecting latching memberof the cylindrical head of the parallel guide insert in the longitudinalaperture of the head end of the handle of the outer dilator tube insuresthat the parallel guide insert remains in a fixed position in the outerdilator tube when the parallel guide insert is secured with the lockingpin. A single guide wire or K wire or other device may be passed throughone or more of the bores of the parallel guide insert, or multiple guidewires or K wires or other devices may be passed through a plurality ofthe bores simultaneously, as desired. However, the parallel guide insertmay be provided without a latching member, in order to allow theparallel guide member to be rotated freely to allow alignment of thedesired locations of the guide wires through the holes in the parallelguide insert.

Referring to FIG. 32, in another presently preferred variation of the atleast one additional or outer dilator tube, such as in the embodiment ofFIGS. 13-18 for example, the outer dilator tube 440 includes a parallelguide insert 442, shown in FIG. 33. The outer dilator tube has a distalend 444 with an angled tip 446, and a proximal end 448 to which a handle450 is connected at the extreme proximal or head end 452 of the outerdilator tube. The head end of the outer dilator tube includes a radialaperture 454 for receiving the locking pin 456, and a longitudinalaperture 458 for receiving a distally projecting latching member 460 ofthe cylindrical head 462 of the parallel guide insert. The outer dilatortube has an inner bore 464 with proximal and distal openings.

The parallel guide insert includes a main cylindrical shaft 465connected at a proximal end 466 to the cylindrical head of the parallelguide insert. The parallel guide insert includes a plurality oflongitudinal bores 468 extending the length of the parallel guide insertfrom the angled distal end 470, with distal openings visible in FIG. 33,to proximal openings (not shown) in the cylindrical head of the parallelguide insert. The insertion of the distally projecting latching memberof the cylindrical head of the parallel guide insert in the longitudinalaperture of the head end of the handle of the outer dilator tube insuresthat the parallel guide insert remains in a fixed position in the outerdilator tube when the parallel guide insert is secured with the lockingpin. The angled tips of the outer dilator tube and the parallel guideinsert are beveled or angled at a common angle with respect to thelongitudinal axis of the dilation introducer, so that the angled tips ofthe outer dilator tube and the parallel guide insert can be alignedtogether generally parallel to the surface of the soft tissue to bedilated, with the bore and dilation passage of the dilation introduceraligned at a predetermined desired angle with respect to the soft tissueto be dilated and the bone tissue to be treated. A single guide wire orK wire or other device may be passed through one or more of the bores ofthe parallel guide insert, or multiple guide wires or K wires or otherdevices may be passed through a plurality of the bores simultaneously,as desired.

Referring to FIG. 34, in a variation of the outer dilator tube of theembodiment of FIGS. 32-33, the distal tip 480 of an outer dilator tube482 may be angled or beveled, and may include a plurality of spikes 484to provide for increased traction of the tip of the outer dilator tubeon bone tissue. The spikes may be formed of radiopaque material, such asgold, platinum, tantalum or the like, for use with fluoroscopy. As isillustrated in FIG. 35, a parallel guide 486 disposed in the outerdilator tube has a distal tip 488 that may optionally also be providedwith a plurality of embedded spikes 490 for increased traction on bonetissue. The spikes of the outer dilator tube and parallel guide mayformed with a rounded shape so as to deflect soft tissue duringdilation, and to provide increased traction with bone upon completion ofthe insertion of the dilator.

Referring to FIGS. 36-43, the invention provides for a fifth presentlypreferred embodiment of a dilation introducer 500, which is similar tothe embodiment illustrated in FIGS. 8-12, and which is shown in anunlocked configuration in FIG. 36. Referring to FIGS. 36-37, thedilation introducer includes a first or inner dilator tube 502 havingdistal end (not shown) and a proximal end 504 with a cylindrical head506. The means for removably connecting the first and second dilatortubes together in a locked configuration includes a first latchingmember 508, having a shaft 510 and a latching end 512, such as a hook,projecting from the cylindrical head toward the distal end, andconnected to a locking button 514, which extends transversely outthrough a side aperture 516 in the cylindrical head. The locking buttonincludes a shaft 518 and an enlarged head 520 connected to the shaft,and the locking button is biased outwardly from the cylindrical head bya spring 522. The latching member is received in an upper aperture 524of the adjacent cylindrical head of a second or intermediate dilatortube 526, having a side opening latching chamber 528 for retaining thelatching end of the latching member when the locking button is biasedoutwardly by its spring, to lock the cylindrical heads of the first andsecond dilator tubes together. The cylindrical heads of the first andsecond dilator tubes can be unlocked and separated by manuallydepressing the locking button to move the latching member inwardly andthe latching end of the latching member inwardly out of the side openinglatching chamber. In all other aspects, the first dilator tube isessentially the same as the first dilator tube of the embodiment ofFIGS. 8-12.

The second or intermediate dilator tube 526 of the dilation introducerhas a distal end (not shown) and a proximal end 530 with a cylindricalhead 532. The means for removably connecting the second and thirddilator tubes together in a locked configuration includes a secondlatching member 534, having a shaft 536 and a latching end 538, such asa hook, projecting from the cylindrical head toward the distal end, andconnected to a second locking button 540, which extends transversely outthrough a side aperture 542 in the cylindrical head. The locking buttonincludes a shaft 544 and an enlarged head 546 connected to the shaft,and the locking button is biased outwardly from the cylindrical head bya spring 548. The latching member is received in an upper aperture 550of the adjacent cylindrical head of a third or second intermediatedilator tube 552, having a side opening latching chamber 554 forretaining the latching end of the latching member when the lockingbutton is biased outwardly by its spring, to lock the cylindrical headsof the second and third dilator tubes together. The cylindrical heads ofthe second and third dilator tubes can be unlocked and separated bymanually depressing the second locking button to move the latchingmember inwardly and the latching end of the latching member inwardly outof the side opening latching chamber. In all other aspects, the seconddilator tube is essentially the same as the second dilator tube of theembodiment of FIGS. 8-12.

The third, or second intermediate, dilator tube 552 of the dilationintroducer has a distal end (not shown) and a proximal end 556 with acylindrical head 558. The means for removably connecting the thirddilator tube and the outer dilator tube 560 together in a lockedconfiguration includes a third latching member 562, having a shaft 564and a latching end 566, such as a hook, projecting from the cylindricalhead toward the distal end, and connected to a third locking button 568,which extends transversely out through a side aperture 570 in thecylindrical head. The third locking button includes a shaft 572 and anenlarged head 574 connected to the shaft, and the third locking buttonis biased outwardly from the cylindrical head by a spring 576. Thelatching member is received in an upper aperture 578 of the adjacentcylindrical head 580 of the outer dilator tube, having a side openinglatching chamber 582 for retaining the latching end of the latchingmember when the locking button is biased outwardly by its spring, tolock the cylindrical heads of the third and outer dilator tubestogether. The cylindrical heads of the third and outer dilator tubes canbe unlocked and separated by manually depressing the third lockingbutton to move the latching member inwardly and the latching end of thelatching member inwardly out of the side opening latching chamber. Inall other aspects, the third dilator tube is essentially the same as thesecond dilator tube of the embodiment of FIGS. 8-12.

Referring to FIG. 36, the outer dilator tube includes a distal end (notshown) and a proximal end 584 to which a handle 586 is connected at itscylindrical head end. The head end of the handle preferably includes aplurality of the upper apertures 578 connected to corresponding sideopening latching apertures 582 for receiving the latching member of theadjacent dilator tube cylindrical head, as is illustrated in FIG. 40.Although three locking locations 588 of the upper apertures andcorresponding side opening latching apertures in the cylindrical head ofthe outer dilator tube are shown, more or fewer locking locations may beprovided, and the locking locations may be provided at variouspositions, to aid in user flexibility as to which hand to use during thedilation procedure, as well as varying the position of the inner dilatortubes and optionally a parallel guide member during use or guide pinplacement. In all other aspects, the outer dilator tube is essentiallythe same as the outer dilator tube of the embodiment of FIGS. 8-12.

Referring to FIGS. 38 and 39, in a variation of the embodiment shown inFIGS. 36 and 37, the side opening latching chambers of the cylindricalheads of the dilator tubes may be closed so as to form covered latchingchambers 590 a, b, c for the latching members. In all other aspects, thevariation shown in FIGS. 38 and 39 is essentially the same as in FIGS.36 and 37.

Referring to FIGS. 41-43, in another variation, an outer dilation tube600 may be provided with a light emitter 602, such as one or more lightemitting diodes (LEDs) or the end of a fiber optic, connected to orembedded in the tubular shaft 604 of the outer dilation tube, andpreferably near the distal end 606 of the tubular shaft. As isillustrated in FIGS. 41 and 42, the light emitter may be an LED embeddedin the wall 608 of the tubular shaft, with the LED directed toilluminate the interior, exterior, or distal edge of the tubular shaftof the outer dilation tube. As is shown in FIG. 42, one or moreelongated energy conducting members 610, such as electrically conductivewires or fiber optics, for example, may be embedded in the tubularshaft, for conducting electricity or light to the light emitter.Referring to FIG. 41, the handle 612 of the outer dilator tubepreferably contains one or more batteries 614 connected to a switch 616which is in turn connected to power the light emitter. The handle may beprovided with a battery or batteries, which may be disposable, a switch,resistor and other associated electronics, so that the handle isdisposable, or alternatively the handle may be provided with a connectorfor connection to an external power source. In a presently preferredaspect, the switch is a thumb switch conveniently located on the handleadjacent to the cylindrical head 618 of the outer dilation tube. Thehandle, cylindrical head, and tubular shaft of the outer dilation tubepreferably includes one or more channels 620 for the electrical wiresconnecting the one or more batteries to the switch and to the lightemitter. When the light emitter includes one or more fiber optics, alight source 622 such as one or more LEDs providing light to beconducted through the one or more fiber optics may be placed adjacent tothe switch in the handle, with the one or more fiber optics extendingthrough the wall of the tubular shaft of the outer dilator tube.

Referring to FIG. 43, in another variation of the dilation introducer ofFIG. 41, the one or more elongated energy conducting members, such asone or more wires or one or more fiber optics, may be disposed on theouter surface of the tubular shaft of the outer dilation tube. In apresently preferred aspect, the tubular shaft of the outer dilation tubemay be formed with a groove 620 running longitudinally on the exteriorsurface of the tubular shaft, parallel to the longitudinal axis of theouter dilation tube, to accommodate one or more wires or one or morefiber optics. Alternatively, the one or more elongated energy conductingmembers may be located on the inside of the dilator tube, or may extendthrough the wall of the dilator tube.

Referring to FIGS. 44-46, the present invention also provides for atelescoping expander sleeve 630 that is adapted to be slidably disposedover the shaft of an outer dilator tube of any of the foregoingembodiments for expanding the patient's soft tissue down to the entrypoint on the bone tissue to be treated, while leaving the outer dilatortube in place, or allowing for replacement of the outer dilator tubewith other equipment for treatment of the bone tissue. The tubularproximal portion may optionally be provided with a handle. The expandersleeve may be pre-assembled in combination with one or more of thedilation introducers, adapted to be ready for use. The telescopingexpander sleeve has a first or inner generally tubular section 632,having a tubular proximal portion 634 with an enlarged proximal head636, and a distal portion 638 with at least two substantially identicalopposing active spreader arms 640 (one of which is not visible in FIGS.44-46) connected at one end to the tubular proximal portion and moveableradially at their distal tips 642. The distal tips of the activespreader arms preferably have beveled edges 644 to deflect soft tissueduring insertion of the telescoping expander sleeve.

A second or outer generally tubular section 646 is slidably disposedover the first or inner generally tubular section, and includes atubular proximal portion 648 and a distal portion 650 with at least twosubstantial identical opposing passive spreader flaps 652 interposedbetween the active spreader arms, hingedly connected to the tubularproximal portion at proximal ends 654, and moveable radially at theirdistal tips 656. The distal tips of the passive spreader flapspreferably also have beveled edges to deflect soft tissue duringinsertion of the telescoping expander sleeve. The distal tips of thepassive spreader flaps when placed together in an unexpandedconfiguration have a generally circular configuration, so that thedistal tips of two passive spreader flaps, for example, have asemi-circular configuration. The passive spreader flaps taperprogressively toward their narrowed proximal ends connected to thetubular proximal portion of the outer tubular section. In a presentlypreferred aspect, the passive spreader flaps are connected to thetubular proximal portion of the outer generally tubular section by rings656 passing through apertures 658 and 660 in the adjacent ends of thetubular proximal portion and the passive spreader flaps, respectively.

The active spreader arms are slidably interposed between and engage thepassive spreader flaps, so that as the telescoping expander sleevetelescopes from an extended, unexpanded configuration to a collapsed,expanded configuration, as shown in FIG. 44, the active spreader armsslide from the narrow proximal ends of the passive spreader flaps to thewider distal ends of the passive spreader flaps to spread the distalends of the passive spreader flaps apart, which also forces the distalends of the active spreader arms apart, as shown in FIG. 46. In apresently preferred aspect, the distal ends of the active spreader armsare slidably connected to slots 662 extending along the inner edges 664of the passive spreader flaps by loops or rings 666, such as loops ofnylon filament or metal rings, for example, which pass through apertures668 in the distal ends of the active spreader arms. Telescoping ofexpander sleeve from a collapsed, expanded configuration to an extended,unexpanded configuration thus slides the distal ends of the activespreader arms of the inner tubular section from the wide distal ends ofthe passive spreader flaps along the inner edges of the passive spreaderflaps to the narrowed proximal ends of the passive spreader flaps, tobring the passive spreader flaps together. The purpose of the activespreader arms and passive spreader flaps is to facilitate the creatingof a larger working area adjacent to bone or bone tissues being treated.The spreader arms and flaps may optionally be covered by an expandablematerial, such as latex, for example, with a central through holepermitting operation of the device, to cover the spreader arms and flapsto prevent tissues from being pressed into cavities of the telescopingexpander sleeve.

In the foregoing embodiments, the components of the dilation introducermay be formed from plastic, stainless steel, or similar materials orcombinations thereof, that can be readily sterilized and packaged readyfor use, after which the dilation introducer may be disposed of orresterilized for subsequent use, as desired. The dilator tubes may beradioluscent, with radiopaque markers located on the tips of one or moreof the dilator tubes. The tip of the first dilator may also be scored,grooved, or otherwise be provided with a rough surface, to preventmigration. The dilation introducer may also have curved or otherwisenon-linear dilator tubes, and the dilation introducer may also have anon-cylindrical shape, such as an oval shape, for example, to allow thedilation introducer to be inserted around objects or a patient's organs.

It should also be appreciated that one or more devices can be insertedthrough the same dilation introducer, and that the dilation introducercan be repositioned within the same incision for fixation of multipledevices. In addition, fiber optic devices may be inserted through orintegrated with the dilation introducer for visual inspection of thetarget area. While particular locking features have been described forthe different embodiments of the dilation introducer, any combination oflocking features or alternate locking features may be utilized. Theouter dilator tube may not be locked, and a handle on the outer dilatortube may simply be used as a stop. It should also be appreciated thatwhile the invention has been described as being used in the context oforthopedic surgery, and more particularly for implantation of bonefixation devices, the dilation introducer of the invention can also beuseful in dilation of soft tissue for percutaneous, minimally invasivesurgical procedures such as nephrostomy, neurosurgery, heart valverepair or replacement, gastrointestinal surgery such as for gall bladderor gall stone surgery, hernia removal, transjugular intrahepaticportal-systemic shunt (TIPS) procedures for treatment of the liver, andthe like.

It will be apparent from the foregoing that, while particular forms ofthe invention have been illustrated and described, various modificationscan be made without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the invention belimited, except as by the appended claims.

1. In a dilation introducer for surgery on an internal body structure,the dilation introducer having a locked assembled configuration forinitial placement of the dilation introducer against a patient's bonetissue to be treated, and an unlocked, collapsed configuration dilatingthe patient's soft tissue down to the tissue to be treated to a desireddegree of dilation to permit minimally invasive surgical procedures onthe patient's tissue to be treated, the improvement in the dilationintroducer comprising: at least one dilator tube having a distal end anda proximal end, the distal end of the at least one dilator tubeincluding a plurality of spikes.
 2. The dilation introducer of claim 1,wherein said spikes are formed of radiopaque material.
 3. The dilationintroducer of claim 1, wherein said spikes are formed are formed with arounded shape so as to deflect soft tissue.
 4. The dilation introducerof claim 1, further comprising a parallel guide insert adapted to bereceived in said at least one additional dilator tube, said parallelguide insert including a main cylindrical shaft having a proximal endconnected to a cylindrical head, and a plurality of longitudinal boresextending the length of the parallel guide insert through the maincylindrical shaft and cylindrical head, and wherein parallel guideinsert has a distal tip with a plurality of spikes.
 5. The dilationintroducer of claim 4, wherein said spikes are formed of radiopaquematerial.
 6. The dilation introducer of claim 4, wherein said spikes areformed are formed with a rounded shape so as to deflect soft tissue. 7.A dilation introducer for surgery on an internal structure to betreated, the dilation introducer having a locked assembled configurationfor initial placement of the dilation introducer against a patient'stissue to be treated, and an unlocked, collapsed configuration dilatingthe patient's soft tissue down to the tissue to be treated to a desireddegree of dilation to permit minimally invasive surgical procedures onthe patient's tissue to be treated, comprising: a first dilator tubehaving a distal end with a tapered tip and a proximal end with acylindrical head; a second dilator tube, the first dilator tube beingremovably received in the second dilator tube for slidable telescopingmovement within the second dilator tube, the second dilator tube havinga distal end with a tapered tip and a proximal end with a cylindricalhead, and an inner lumen with a distal opening and a proximal opening;and means for removably connecting the first and second dilator tubestogether in a locked configuration including a first latching memberdisposed in the cylindrical head of the first dilator tube, the firstlatching member having locking button connected transversely to a shaftwith a latching end projecting from the cylindrical head of the firstdilator tube toward the distal end of the first dilator tube, thelocking button extending transversely from the shaft through a sideaperture in the cylindrical head of the first dilator tube, the lockingbutton being biased outwardly from the cylindrical head, the firstlatching member being received in an upper aperture of the cylindricalhead of the second dilator tube, the upper aperture of the cylindricalhead of the second dilator tube having a latching chamber for retainingthe latching end of the latching member when the locking button isbiased outwardly, to lock the cylindrical heads of the first and seconddilator tubes together, the locking button being moveable inwardly tomove the latching member inwardly and the latching end of the latchingmember inwardly out of the latching chamber.
 8. The dilation introducerof claim 7, further comprising at least one additional dilator tube, thesecond dilator tube being removably received in the at least oneadditional dilator tube for slidable telescoping movement within the atleast one additional dilator tube, the at least one additional dilatortube having a distal end and a proximal end with a cylindrical head, aninner lumen with a distal opening and a proximal opening, the distal endhaving a tapered tip, the second dilator tube and the at least oneadditional dilator tube having an unlocked configuration in which the atleast one additional dilator tube is permitted to slidably telescopeover the second dilator tube to dilate the patient's soft tissue at thedistal end of the dilation introducer; and means for removablyconnecting the second dilator tube and the at least one additionaldilator tube together in a locked configuration including a secondlatching member disposed in the cylindrical head of the second dilatortube, the second latching member having locking button connectedtransversely to a shaft with a latching end projecting from thecylindrical head of the second dilator tube toward the distal end of thesecond dilator tube, the locking button extending transversely from theshaft through a side aperture in the cylindrical head of the seconddilator tube, the locking button being biased outwardly from thecylindrical head, the second latching member being received in an upperaperture of the cylindrical head of the at least one additional dilatortube, the upper aperture of the cylindrical head of the at least oneadditional dilator tube having a latching chamber for retaining thelatching end of the second latching member when the locking button isbiased outwardly, to lock the cylindrical heads of the second and atleast one additional dilator tubes together, the locking button beingmoveable inwardly to move the second latching member inwardly and thelatching end of the second latching member inwardly out of the latchingchamber.
 9. The dilation introducer of claim 8, wherein said at leastone additional dilator tube comprises a handle connected to the proximalend of said at least one additional dilator tube, and the cylindricalhead of said at least one additional dilator tube including a pluralityof said upper apertures each including one said latching chamber forreceiving the second latching member.
 10. In a dilation introducer fororthopedic surgery, the dilation introducer having a locked assembledconfiguration for initial placement of the dilation introducer against apatient's tissue to be treated, and an unlocked, collapsed configurationdilating the patient's soft tissue down to the tissue to be treated to adesired degree of dilation to permit minimally invasive surgicalprocedures on the patient's tissue to be treated, the improvement in thedilation introducer comprising: at least one dilator tube having atubular shaft, a distal end and a proximal end, an inner lumen with adistal opening and a proximal opening; and a light emitter disposed insaid at least one additional dilator tube.
 11. The dilation introducerof claim 10, wherein said light emitter comprises a light emittingdiode.
 12. The dilation introducer of claim 11, wherein said lightemitting diode is embedded in said tubular shaft of said at least onedilator tube.
 13. The dilation introducer of claim 10, wherein saidlight emitter comprises a fiber optic.
 14. The dilation introducer ofclaim 13, wherein said fiber optic is embedded in said tubular shaft ofsaid at least one dilator tube.
 15. The dilation introducer of claim 10,wherein said at least one dilator tube comprises a handle and a switchfor controlling said light emitter, and at least one battery is disposedin said handle, said at least one battery being connected to said switchto power said light emitter.
 16. The dilation introducer of claim 13,wherein said light emitter further comprises a light source providinglight conducted to said at least one fiber optic.
 17. The dilationintroducer of claim 10, wherein said light emitter comprises at leastone elongated energy conducting member disposed on an outer surface ofthe tubular shaft of said at least one dilator tube.
 18. The dilationintroducer of claim 17, wherein said at least one elongated energyconducting member is disposed in a groove on the exterior surface of thetubular shaft.
 19. A telescoping expander sleeve adapted to be slidablydisposed over a shaft of a dilator tube for dilating a patient's softtissue down to tissue to be treated to a desired degree of dilation topermit minimally invasive surgical procedures on the patient's tissue tobe treated, the telescoping expander sleeve being moveable between anextended, unexpanded configuration and a collapsed, expandedconfiguration, the telescoping expander sleeve comprising: a firstgenerally tubular section having a tubular proximal portion and a distalportion, the tubular proximal portion having an enlarged proximal head,and the distal portion including at least two active spreader arms eachhaving a proximal end and a distal tip, said at least two activespreader arms being connected at the proximal end, respectively, to thetubular proximal portion, said distal tips of said at least two activespreader arms being moveable radially between an unexpandedconfiguration and an expanded configuration; a second generally tubularsection slidably disposed over the first generally tubular section, saidsecond generally tubular section including a tubular proximal portionand a distal portion including at least two passive spreader flaps eachhaving a narrow proximal end and a wide distal tip, said proximal endsof said at least two passive spreader flaps being hingedly connected tosaid tubular proximal portion, said distal tips of said at least twopassive spreader flaps being moveable radially between an unexpandedconfiguration and an expanded configuration, said at least two activespreader arms slidably engaging said at least two passive spreaderflaps, so that as the telescoping expander sleeve telescopes from theextended, unexpanded configuration to a collapsed, expandedconfiguration, said at least two active spreader arms slide from thenarrow proximal ends of said at least two passive spreader flaps to thewider distal ends of the passive spreader flaps to spread the distalends of said at least two passive spreader flaps apart and to spread thedistal ends of said at least two active spreader arms apart.
 20. Thetelescoping expander sleeve of claim 19, wherein the distal tips of saidat least two active spreader arms have beveled edges to deflect softtissue during insertion of the telescoping expander sleeve.
 21. Thetelescoping expander sleeve of claim 19, wherein the distal tips of saidat least two passive spreader flaps have beveled edges to deflect softtissue during insertion of the telescoping expander sleeve.
 22. A guidewire assembly for use with a telescoping dilation introducer intreatment of soft tissue, to provide a surface against which thetelescoping dilation introducer can be pushed during operation of thetelescoping dilation introducer, comprising: an elongated tubularsection having a proximal end, a distal end, an internal bore, and afrustoconical distal tip with a narrowed portion at the distal end andan enlarged flat shoulder at a proximal portion of the frustoconicaldistal tip; and an elongated generally cylindrical section removablyreceived in said internal bore of said elongated tubular section, theelongated generally cylindrical section having a proximal enlarged headand an elongated body portion, said elongated body portion having aproximal end and a distal end, said distal end having a pointed distaltip, such that when said elongated generally cylindrical section isreceived in said elongated tubular section, said pointed distal tipextends out of the distal end of said frustoconical distal tip topresent a sharp point that can be positioned in soft tissue, and suchthat when said elongated generally cylindrical section is thereafterremoved, said enlarged flat shoulder of said frustoconical distal tipprovides a surface against which a telescoping dilation introducer canbe pushed for operation of the telescoping dilation introducer intreatment of soft tissue.
 23. The guide wire assembly of claim 22,wherein said elongated body portion of said elongated generallycylindrical section includes a proximal section adjacent to saidproximal enlarged head and an elongated main section connected to theproximal section, said proximal section having a diameter larger than anouter diameter of said elongated tubular section, and said elongatedmain section having a diameter narrower than the diameter of saidinternal bore of said elongated tubular section so as to be receivablein said internal bore of said elongated tubular section, such that whensaid elongated main section is received in said internal bore of saidelongated tubular section and said proximal section of the elongatedbody portion of the elongated generally cylindrical section is seatedagainst said proximal end of said elongated tubular section, saidpointed distal tip extends out of said frustoconical distal tip of saidelongated tubular section so that said guide wire assembly presents apointed distal end.